1. Technical Field
Example embodiments of the present invention relate in general to the field of image editing, and more particularly, to a matting method for extracting a foreground object by extracting neighboring pixels, each of which establishes either a nonlocal relationship or a local relationship with each pixel constituting an input image, and performing high-quality matting using the neighboring pixels, and an apparatus for performing the matting method.
2. Related Art
Recently, with the popularization of user terminals, such as a smartphone, a tablet PC, and a personal digital assistant (PDA), and the development of information processing technology, active research on image editing techniques that enable users to capture an image or record a video using their terminals and edit the captured image or recorded video to their taste is in progress.
Image editing techniques aim to create a new composite image by extracting a portion of one image upon request of a user and combining the extracted portion with another image. To this end, the image editing techniques inevitably require an image matting technique for precisely extracting a target object for editing from an image.
Generally, the image matting technique uses a trimap to extract a foreground object from an input image. The trimap of an image may refer to an image that schematically divide a foreground region, a background region, and an unknown region for the image.
Accordingly, what was proposed was a matting technique that allows for extracting a foreground object from a received input image and a received trimap of the input image based on a local propagation scheme or a nonlocal propagation scheme.
A local-propagation-based matting technique uses pixels within a predefined range of area in an input image and exhibits an excellent matting performance when a target foreground object represents a soft texture such as fur, but shows a reduced matting performance when the target foreground object includes an area with a complicated feature, such as a hole, which makes it difficult to distinguish the area between a foreground or a background, or the foreground object is represented by a combination of various colors.
On the other hand, the nonlocal-propagation-based matting technique uses pixels with similar characteristics in an input image and exhibits an excellent matting performance when a target foreground object includes an area with a complicated feature, such as a hole, or is represented by a combination of various colors, but shows a reduced matting performance when the object represents a soft texture, such as fur.
As such, the existing matting techniques are limited in that their matting performances drastically vary depending on conditions of a foreground object, such as appearance characteristics or colors, by which the foreground object is represented in an input image.